A field that you must use to avoid starving has 100 mines in it, you can remove [on average] 55 of those mines using a locally made and affordable device. The field will be used anyway. Would you deploy the device?
You're leading a demining team. A village have asked you to clear a field that they rely on for crops (other areas are too rocky or haven't enough good soil). You can send out some locally produced cheap demining devices first that will remove about 50% of the mines reducing the risk to your team. Would you deploy the device?
"is not useful" you say?
Your position appears to be a counterpoint to a statement that these devices will clear all mines effectively from all areas in all conditions. I've not seen anyone make such a claim. Your position is only tenable when a mined area is not needed by the locals.
The devices, and the beautifully made film, have another purpose which is far from useless too - attracting attention and thence funding for demining projects.